Multi-Antenna Techniques for Next Generation Cellular Communications

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School of Electrical Engineering | Doctoral thesis (article-based) | Defence date: 2016-09-02
Degree programme
138 + app. 82
Aalto University publication series DOCTORAL DISSERTATIONS, 156/2016
Future cellular communications are expected to offer substantial improvements for the pre- existing mobile services with higher data rates and lower latency as well as pioneer new types of applications that must comply with strict demands from a wider range of user types. All of these tasks require utmost efficiency in the use of spectral resources. Deploying multiple antennas introduces an additional signal dimension to wireless data transmissions, which provides a significant alternative solution against the plateauing capacity issue of the limited available spectrum. Multi-antenna techniques and the associated key enabling technologies possess unquestionable potential to play a key role in the evolution of next generation cellular systems. Spectral efficiency can be improved on downlink by concurrently serving multiple users with high-rate data connections on shared resources. In this thesis optimized multi-user multi-input multi-output (MIMO) transmissions are investigated on downlink from both filter design and resource allocation/assignment points of view. Regarding filter design, a joint baseband processing method is proposed specifically for high signal-to-noise ratio (SNR) conditions, where the necessary signaling overhead can be compensated for. Regarding resource scheduling, greedy- and genetic-based algorithms are proposed that demand lower complexity with large number of resource blocks relative to prior implementations. Channel estimation techniques are investigated for massive MIMO technology. In case of channel reciprocity, this thesis proposes an overhead reduction scheme for the signaling of user channel state information (CSI) feedback during a relative antenna calibration. In addition, a multi-cell coordination method is proposed for subspace-based blind estimators on uplink, which can be implicitly translated to downlink CSI in the presence of ideal reciprocity. Regarding non-reciprocal channels, a novel estimation technique is proposed based on reconstructing full downlink CSI from a select number of dominant propagation paths. The proposed method offers drastic compressions in user feedback reports and requires much simpler downlink training processes. Full-duplex technology can provide up to twice the spectral efficiency of conventional resource divisions. This thesis considers a full-duplex two-hop link with a MIMO relay and investigates mitigation techniques against the inherent loop-interference. Spatial-domain suppression schemes are developed for the optimization of full-duplex MIMO relaying in a coverage extension scenario on downlink. The proposed methods are demonstrated to generate data rates that closely approximate their global bounds.
Supervising professor
Wichman, Risto, Prof., Aalto University, Department of Signal Processing and Acoustics, Finland
baseband filter design, resource scheduling, cellular systems, massive MIMO, full-duplex, multi-antenna calibration, RF transceivers
  • [Publication 1]: U. Ugurlu, R. Wichman, C. Ribeiro, C, Wijting. A Novel Joint Precoder and Receiver Design with Imperfect CSI for Multi-User MIMO Downlink. In IEEE 80th Vehicular Technology Conference (VTC Fall), Vancouver, BC, pp. 1–5, September 2014.
    DOI: 10.1109/VTCFall.2014.6965827 View at publisher
  • [Publication 2]: U. Ugurlu, R. Wichman, C. Ribeiro, C. Wijting. Iterative Genetic and Greedy-Based Algorithms for Multi-Carrier Multi-User Scheduling in MIMO Systems with Successive Zero Forcing. In IEEE 80th Vehicular Technology Conference (VTC Fall), Vancouver, BC, pp. 1–5, September 2014.
    DOI: 10.1109/VTCFall.2014.6966024 View at publisher
  • [Publication 3]: U. Ugurlu, R. Wichman, C. Ribeiro, C. Wijting. Adaptive Channel Quantization on TDD Reciprocity Performance of Relative Antenna Calibration. In IEEE 80th Vehicular Technology Conference (VTC Fall), Vancouver, BC, pp. 1–5, September 2014.
    DOI: 10.1109/VTCFall.2014.6965852 View at publisher
  • [Publication 4]: U. Ugurlu, R. Wichman, C. Ribeiro, C. Wijting. Coordinated Optimization of EVD-Based Channel Estimators in Multi-Cell Massive MIMO Networks. In IEEE International Communications Workshops (ICC) on 5G & Beyond - Enabling Technologies and Applications, London, UK, pp. 1–5, June 2015.
    DOI: 10.1109/ICCW.2015.7247355 View at publisher
  • [Publication 5]: U. Ugurlu, R. Wichman, C. Ribeiro, C. Wijting. A Multipath Extraction Based CSI Acquisition Method for FDD Cellular Networks with Massive Antenna Arrays. IEEE Transactions on Wireless Communications, vol. 15, no. 4, 2940–2953, December 2015.
    DOI: 10.1109/TWC.2015.2513402 View at publisher
  • [Publication 6]: U. Ugurlu, R. Wichman, C. Ribeiro, C. Wijting. Multipath Phase Indication (MPI) Feedback for CSI Acquisition in FDD Massive MIMO. In IEEE 25th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), Hong Kong, pp. 1–5, August 2015.
    DOI: 10.1109/PIMRC.2015.7343364 View at publisher
  • [Publication 7]: U. Ugurlu, T. Riihonen, R. Wichman. Optimized In-Band Full-Duplex MIMO Relay under Single-Stream Transmission. IEEE Transactions on Vehicular Technology, vol. 65, no. 1, 155–168, January 2015.DOI: 10.1109/TVT.2015.2396684
  • [Publication 8]: U. Ugurlu, R. Wichman, T. Riihonen, C. Ribeiro, C. Wijting. Power Control and Beamformer Design for the Optimization of Full-Duplex MIMO Relays in a Dual-Hop MISO Link. In IEEE 9th Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM), Oulu, Finland, pp. 545–549, June 2014.
    DOI: 10.4108/icst.crowncom.2014.255673 View at publisher